This portable, self-contained capacitance compensator for null measurement of ionization currents was developed around 1931 by Lauriston S. Taylor at the National Bureau of Standards. The instrument was used to make accurate measurements of small charges or currents by electrostatic means, with the goal of measuring the ionization of air by x-rays to determine the international unit of x-ray quantity, the roentgen. The instrument consists of a string electrometer mounted on a 2.6 x 8 inch (6.4 x 20.32 cm) aluminum box. The box contains batteries, a standard capacitor, and a potentiometer.

Subject

Electronics

Scientific Discipline

Electronics; Physics;

Publications

L. S. Taylor, Accurate measurement of small electric charges by a null method, J. Res. Natl. Bur. Stand. Tech. 6 (5), 807 (1931) RP 306.; L. S. Taylor and W.R. Tilley, X-Ray Measurements and Protection 1913-1964: the Role of the National Bureau of Standards and the National Radiological Organizations, National Bureau of Standards Special Publication 625, (1981).

Object Dimensions

30 x 24 x 18 cm

Rights

Use of the images from NIST Digital Archives is not restricted, but a statement of attribution is required. Please use the following attribution statement: "National Institute of Standards and Technology Digital Collections, Gaithersburg, MD 20899"